Can Link-Seal be used above 250 °F (121 °C)?

Standard EPDM compounds are typically limited near 250 °F (121 °C). For higher temperatures, select the T (Silicone) hardware/elastomer option and confirm the GPT chemical/temperature chart — this tool does not replace manufacturer limits.

What if annular space is too large or too small?

If C 85 mm (≈ 0.47–3.35 in), the UI warns that the gap is outside the standard Link-Seal chart. Resize the sleeve, change the core-drill diameter, or use a Century-Line / manufacturer oversized sleeve solution.

Does this replace the GPT sizing chart?

No. This is a field screening calculator using published free thickness / belt width. Always verify model and link count on the current GPT Link-Seal sizing chart before procurement. Link-Seal® is a registered trademark of GPT Industries — this app is not affiliated with or endorsed by GPT Industries.

2" Link-Seal & Penetration Sleeve Sizing | ASME & API Calculations

1. Core Formula & Variable Definitions

GPT Industries Link-Seal Modular Sealing System (manufacturer catalog) · Century-Line / wall sleeve pairing practice · ASME B36.10M — pipe OD reference

C = Sleeve ID − Pipe OD2

D_p = OD + 2 · t_free · N = round(π · D_p / w_belt)

GPT Link-Seal modular mechanical seal screening · Century-Line sleeve pairing

Models LS-200 … LS-575C warn <12 mm / >85 mmRating 0.14 MPa · 20 psigN min 3 links

Select a Link-Seal model whose free (unexpanded) thickness is slightly less than the annular clearance C and whose screening envelope covers C. Pitch diameter Dp is the link-bolt / belt centerline (OD + 2·t_free) used only to compute N. Ideal minimum sleeve ID uses the same geometry to seat free thickness (C ≈ t_free) — do not confuse Dp with a procurement sleeve catalog size when the entered hole differs. Hardware suffixes: C (zinc CS), S316, T (silicone HT). Continuous service screening ≈ 0.14 MPa (1.38 bar) / 12.2 m H₂O · 20 psig / 40 ft head — confirm the current GPT catalog. Link-Seal® is a registered trademark of GPT Industries; this app is an independent screening tool.

C (Annular clearance) — Radial gap between pipe OD and sleeve/hole ID: C = (ID − OD)/2 (mm or in).
t_free (Free thickness) — Unexpanded Link-Seal rubber thickness for the selected model (mm or in).
w_belt (Belt width / link pitch) — Center-to-center pitch used for link count (mm or in).
D_p (Pitch diameter (bolt centerline)) — Dp = OD + 2·t_free — diameter through link-bolt / belt centers used to compute N. Not a substitute label for the entered sleeve ID.
ID_ideal (Ideal minimum sleeve ID) — OD + 2·t_free — minimum sleeve/hole bore that seats free thickness when C ≈ t_free. Compare to the entered sleeve ID.
N (Number of links) — N = round(π·Dp / w_belt), minimum 3 for a closed belt.
OD (Pipe outside diameter) — Carrier pipe OD (from NPS Sch 40/STD or manual override).
ID (Sleeve / hole ID (entered)) — Steel sleeve inside diameter or finished core-drilled hole diameter as entered.

2. Allowances, Tolerances & Standards

Model matching uses screening envelopes ≈ 0.80–1.20 × free thickness. Outside ~12–85 mm annular space, resize the sleeve or consider Century-Line oversized sleeves.

Annular clearance C(ID − OD) / 2

Must be positive. Free thickness should be slightly less than C so expansion seals the annulus.

Out-of-range warningC < 12 mm or C > 85 mm

UI warns when annular space is outside the standard Link-Seal chart. Resize sleeve or use Century-Line.

Link count roundingNearest integer (≥ 3)

Screening N = round(π·Dp / belt width). Confirm even-count or chart counts on the GPT sheet when required.

Pressure rating0.14 MPa / 20 psig

Typical continuous modular-seal screening (≈ 1.38 bar · 12.2 m H₂O · 40 ft head). Higher heads need manufacturer confirmation. Live results follow the Metric/Imperial navbar toggle.

Dp vs Ideal sleeve IDSame formula, different meaning

Dp = link-bolt centerline for N. Ideal minimum sleeve ID = OD + 2·t_free seats free thickness. Entered sleeve ID may differ; always compare both.

Model free-thickness / belt chart is shown once under Calculation Results (Link-Seal model chart). Confirm values on the current GPT catalog before purchase.

3. Material & Code Limitations

Hardware suffix and elastomer compound set corrosion and temperature capability. This calculator does not derate for fire, hydrocarbons, or vacuum.

Material Group	Temperature Range	Allowable Stress / Limit	Engineering Notes
C — Carbon steel zinc hardware	EPDM / standard compound (typical ≤ ~121 °C / 250 °F)	0.14 MPa / 20 psig screening	Default plant hardware for buried / wet walls when stainless is not specified.
S316 — Stainless 316 hardware	Same elastomer family unless specified	0.14 MPa / 20 psig screening	Use in corrosive or coastal atmospheres where zinc CS is inadequate.
T — Silicone high-temperature	Silicone service (confirm GPT sheet; often > standard EPDM)	Confirm catalog	Not a substitute for fire-stop listed assemblies. Check chemical compatibility.
Century-Line / oversized sleeves	N/A	When C out of chart	If annular space is too large/small for LS-200–LS-575, resize the sleeve or use manufacturer Century-Line guidance.

Code Applicability & Safety Boundaries

Screening Purpose Only: preliminary sizing from published reference data — not a substitute for official engineering calculations, design review, or manufacturer certification.
Verification Required: always confirm model, link count, and clearances against the current official GPT Industries Link-Seal® sizing chart and installation manual before procurement or installation.
No Warranty: this tool is provided AS IS. FieldEngineersKit assumes no liability for errors, omissions, or damages arising from use of these results.
Trademark Notice: Link-Seal® and Century-Line® are registered trademarks of GPT Industries. This application is an independent utility and is not affiliated with, sponsored, or endorsed by GPT Industries.
Do not use above manufacturer temperature / chemical limits (e.g. continuous > 250 °F / 121 °C without the correct compound).

4. Step-by-Step Worked Example

Field VerificationShow

Size a Link-Seal for NPS 4 Sch 40 carrier pipe (OD = 114.3 mm) through a steel wall sleeve with ID = 190 mm, carbon-steel zinc hardware.

Pipe:NPS 4 Sch 40 · OD 114.3 mmSleeve ID:190 mmOpening:Steel pipe sleeveHardware:C — CS zinc

1

Compute annular clearance

Formula: C = (ID - OD) / 2

C = (190 − 114.3) / 2 = 75.7 / 2

Result:C = 37.85 mm

Within the 12–85 mm screening window.

2

Match Link-Seal model

LS-400 free thickness = 36.3 mm (envelope 29.0–43.6 mm). Free t is slightly under C.

Result:Select LS-400

LS-425 free t = 28.4 mm is farther from C; LS-400 is the closest valid match.

3

Pitch diameter (bolt centerline)

Formula: D_p = OD + 2 t_free

Dp = 114.3 + 2 × 36.3 = 114.3 + 72.6

Result:Dp = 186.9 mm (link-bolt centerline)

Dp drives N only — it is not the entered sleeve catalog ID.

4

Number of links

Formula: N = round(π D_p / w_belt)

N = round(π × 186.9 / 63.5) = round(9.25)

Result:N = 9 links

Hero shows LS-400-C × 9 Links.

5

Ideal minimum sleeve ID vs entered ID

Ideal ID = OD + 2·t_free = 186.9 mm (seats free thickness). Entered sleeve ID = 190 mm.

Result:Entered 190 mm ≥ ideal 186.9 mm — acceptable

Screening rating 0.14 MPa (1.38 bar) · 12.2 m H₂O — confirm GPT sheet.

Conclusion: For NPS 4 × 190 mm sleeve: LS-400-C with 9 links, C ≈ 37.9 mm. Confirm the GPT chart and tighten bolts in a star pattern until rubber bulges lightly.

5. Frequently Asked Questions & Technical References

Show

Tighten in a star / criss-cross pattern until the rubber links bulge slightly and seal against both the pipe and the sleeve. Do not drive bolts to metal-to-metal crush. Follow the GPT installation sheet for the model.